I tried to implement my own keygen plug-in for Regkeeper this few days. I have followed the rules of Regkeeper Keygen plug-in. And I have disabled the "Process received mail orders in background", then I had clicked "Generate" button in "Registration Info" tab when Regkeeper got the tested mail order. But it did not give any "Key-info".

And then I used the Delphi version of Sample Key Gens provided with Regkeeper. It gave me the same result after I have compiled it and set the keygen path correctly.